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United States Patent |
5,210,246
|
Tanaka
,   et al.
|
May 11, 1993
|
Amino group-containing silicate composition and dehydrating agent
containing it
Abstract
The present invention relates to a reaction product of a tetraalkoxysilane
or a silicate oligomer obtained by its partial
hydrolysis-dehydration-polycondensation, with an amino alcohol having one
or two hydroxyl groups, and a dehydrating agent comprising such a reaction
product.
The dehydrating agent of the present invention is suitable for dehydrating
a moisture at a level of a few hundreds ppm. Further, since an amino
alcohol is formed by the dehydration, it is particularly useful as a
dehydrating agent for a raw material for the production of a urethane
resin or an epoxy resin.
Inventors:
|
Tanaka; Tetsuya (Fujisawa, JP);
Katano; Hiroaki (Yokohama, JP);
Ohtani; Masaaki (Yokohama, JP)
|
Assignee:
|
Mitsubishi Kasei Corporation (Tokyo, JP);
Dow Mitsubishi Kasei Limited (Tokyo, JP)
|
Appl. No.:
|
688558 |
Filed:
|
June 20, 1991 |
PCT Filed:
|
October 19, 1990
|
PCT NO:
|
PCT/JP90/01347
|
371 Date:
|
June 20, 1991
|
102(e) Date:
|
June 20, 1991
|
PCT PUB.NO.:
|
WO91/05790 |
PCT PUB. Date:
|
May 2, 1991 |
Foreign Application Priority Data
Current U.S. Class: |
556/413; 525/123; 528/45 |
Intern'l Class: |
C07F 007/10; C08G 077/02 |
Field of Search: |
556/413
525/123,127
528/45
|
References Cited
U.S. Patent Documents
3079656 | Mar., 1983 | Emblem et al. | 22/193.
|
4722969 | Feb., 1988 | Huynh-Tran et al. | 525/123.
|
Foreign Patent Documents |
1547331 | Nov., 1968 | FR.
| |
45-26233 | Aug., 1970 | JP.
| |
46-30711 | Sep., 1971 | JP.
| |
1-156368 | Jun., 1989 | JP.
| |
1519657 | Aug., 1978 | GB.
| |
Other References
Chemical Abstracts, vol. 76, No. 16, Apr. 17, 1972, p. 38, Abstract No.
86647v & SU-A-292 489.
|
Primary Examiner: Prescott; Arthur C.
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier & Neustadt
Claims
We claim:
1. An amino group-containing silicate composition obtained by reacting a
silicate oligomer obtained by hydrolyzing, dehydrating and polycondensing
a tetraalkoxysilane at a degree of hydrolysis within a range of from 0 to
65%, with an amino alcohol having one or two hydroxyl groups.
2. The amino group-containing silicate composition according to claim 1,
wherein a silicate oligomer obtained by hydrolyzing, dehydrating and
polycondensing a tetraalkoxysilane within a range of from 0 to 50%, is
used.
3. The amino group-containing silicate composition according to claim 1,
wherein the carbon number of the amino alcohol is from 1 to 30.
4. The amino group-containing silicate composition according to claim 1,
wherein the carbon number of the amino alcohol is from 2 to 10.
5. A dehydrating agent containing an amino groupcontaining silicate
composition obtained by reacting a silicate oligomer obtained by
hydrolyzing, dehydrating and polycondensing a tetraalkoxysilane at a
degree of hydrolysis within a range of from 0 to 65%, with an amino
alcohol having one or two hydroxyl groups.
6. The dehydrating agent according to claim 5, wherein the amino
group-containing silicate composition is the one obtained by reacting the
silicate oligomer with the amino alcohol within a range of hydroxyl group
equivalent/alkoxy equivalent=0.1-1.0.
7. The dehydrating agent according to claim 6, wherein the hydroxyl group
equivalent/alkoxy equivalent is within a range of from 0.4 to 1.0.
8. The dehydrating agent according to claim 5, wherein the silicate
oligomer and the amino alcohol are reacted at a temperature of from
70.degree. to 200.degree. C.
9. The dehydrating agent according to claim 5, wherein the viscosity (at
25.degree. C.) of the amino group-containing silicate composition is from
0.001 to 1000 poise.
10. The dehydrating agent according to claim 5, wherein a substance to be
dehydrated is a polyol.
11. A non-foamed urethane resin obtained by reacting an isocyanate and a
polyol, said polyol or isocyanate, or both said polyol and said isocyanate
having a dehydrating agent added thereto, said dehydrating agent being
obtained by reacting a silicate oligomer with an amino alcohol having one
or two hydroxyl groups, said silicate oligomer obtained by hydrolyzing,
dehydrating and polycondensing a tetraalkoxysilane at a degree of
hydrolysis within the range of from 0 to 65%.
12. The non-foamed urethane resin according to claim 11, which is obtained
by the reaction at a NCO/OH equivalent ratio of from 1.00 to 1.35.
13. A curing agent for an epoxy resin, which comprises an amino
group-containing silicate composition obtained by reacting a silicate
oligomer obtained by hydrolyzing, dehydrating and polycondensing a
tetraalkoxysilane at a degree of hydrolysis within a range of from 0 to
65%, with an amino alcohol having one or two hydroxyl groups.
14. An amino group-containing silicate composition according to claim 1
wherein said silicate comprises units of the formula:
Si(OR).sub.4-2n-x O.sub.n (OR').sub.x (V)
wherein n is a real number of from 0-1.3, x is a real number of from 0.4 to
4, R is an alkyl group, and R' is a monovalent hydrocarbon residue having
an amino group,
or comprises units of the formula:
Si(OR).sub.4-2n-2y O.sub.n (OR"O).sub.y (VI)
wherein n and R have the same meaning as in formula V, y is a real number
of from 0.2 to 2 and R" is bivalent hydrocarbon residue having an amino
group.
15. A dehydrating agent containing an amino groupcontaining silicate
composition according to claim 5 wherein said silicate comprises units of
the formula:
Si(OR).sub.4-2n-x O.sub.n (OR').sub.x (V)
wherein n is a real number of from 0-1.3x is a real number of from 0.4 to
4, R is an alkyl group, and R' is a monovalent hydrocarbon residue having
an amino group,
or units of the formula:
Si(OR).sub.4-2n-2y O.sub.n (OR"O).sub.y (VI)
wherein n and R have the same meanings as in formula V, y is a real number
of from 0.2 to 2 and R" is bivalent hydrocarbon residue having an amino
group.
16. A non-foamed urethane resin obtained by reacting an isocyanate and a
polyol according to claim 11 wherein the dehydrating agent comprises units
of the formula:
Si(OR).sub.4-2n-x O.sub.n (OR').sub.x (V)
wherein n is a real number of from 1-1.3, x is a real number of from 0.4 to
4, R is an alkyl group, and R' is a monovalent hydrocarbon residue having
an amino group,
or units of the formula:
Si(OR).sub.4-2n-2y O.sub.n (OR"O).sub.y (VI)
wherein n and R have the same meaning as in formula V, y is a real number
of from 0.2 to 2 and R" is bivalent hydrocarbon residue having an amino
group.
Description
TECHNICAL FIELD
The present invention relates to an amino group-containing silicate
composition suitable for dehydrating a very small amount of moisture
contained in various chemical reagents. Further, the present invention
relates to a dehydrating agent employing such a composition and a resin
produced by using a raw material dehydrated by means of such a
composition.
BACKGROUND TECHNIQUE
Many chemical reagents and chemical raw materials have their moisture
contents stipulated in the product standards. It is evident from this fact
that it is very important to control or dehydrate the moisture in chemical
reagents and chemical raw materials.
As a dehydration method, it has been common to separate the moisture and
the product by distillation or fractional distillation. However, in many
cases, it is difficult to completely remove the moisture by distillation.
Especially in the case of a substance azeotropically distilled with water
or a substance having a strong affinity with water, it is difficult to
adequately remove the moisture.
Further, there is a method available in which a solid powder such as
molecular sieves or calcium chloride is added to let it adsorb water for
dehydration. In this case, it is necessary to remove the solid powder
having water adsorbed thereon. As a means for such removal, it is common
to employ filtration, but in many cases, it is difficult to remove the
solid having water adsorbed thereon.
For example, the moisture in a polyol of a usual grade used as a raw
material for the production of urethane, is usually from 1000 to a few
hundreds ppm. However, in a case of a grade where the moisture is
particularly unwanted, the moisture is required to be not higher than 150
ppm. To remove the moisture in a polyol to a level of from a few hundreds
ppm to not higher than 150 ppm, molecular sieves or other solid
dehydrating agent, a tetraalkylsilicate or an oligomer obtained by the
hydrolysis-dehydration-polycondensation thereof, is used at present.
However, in the case of a solid dehydrating agent including molecular
sieves, the filtration process is not easy, and in the case of the
tetraalkylsilicate or the oligomer obtained by the
hydrolysis-dehydration-polycondensation thereof, it takes a long time for
dehydration (a few days at room temperature, or about one day at
60.degree. C.).
The present inventors have conducted extensive studies with an aim to
develop a useful substance by the reaction of an amino group-containing
compound with a silicate and have found that a novel composition obtained
by the reaction of a certain specific silicate compound with an amino
compound having hydroxyl groups, is an amino compound having a relatively
low viscosity and a high boiling point, and such a composition readily
reacts with water. The present invention has been accomplished on the
basis of this discovery.
DISCLOSURE OF THE INVENTION
The gist of the present invention resides in an amino group-containing
silicate composition obtained by reacting a tetraalkoxysilane or a
silicate oligomer obtained by hydrolyzing, dehydrating and polycondensing
it at a degree of hydrolysis within a range of not higher than 65%, with
an amino alcohol having one or two hydroxyl groups, and a dehydrating
agent using such a composition.
Now, the present invention will be described in detail. The silicate
compound used in the present invention is a tetraalkoxysilane of the
following formula or its oligomer:
##STR1##
(wherein R.sup.1 to R.sup.4 which may be the same or different, are a
lower alkyl group such as methyl, ethyl, propyl or butyl.)
The silicate oligomer is obtained by hydrolyzing, dehydrating and
polycondensing the above tetraalkoxysilane monomer. The production of the
oligomer is conducted by adding acidic, neutral or alkaline water in a
necessary amount to the tetraalkoxysilane monomer and removing the alcohol
resulting from the reaction (which forms 2 molar times the amount of the
added water).
The reaction is represented as follows:
Si(OR).sub.4 +nH.sub.2 O.fwdarw.Si(OR).sub.4-2n O.sub.n +2nROH (I)
The formula (I) represents the reaction of one molecule of the
tetraalkoxysilane. However, in reality, a plurality of molecules are
polymerized to form an oligomer.
In the present invention, it is preferred to employ an oligomer having a
viscosity of not higher than about 7000 cps (25.degree. C.).
The obtained oligomer is considered to contain not only the one having a
chain structure but also condensates having various structures such as
branched and cyclic structures and mixtures thereof.
The degree of hydrolysis of the silicate is a value calculated in
accordance with the following formula (II), and the amount of water to be
added will be determined depending upon the desired degree of hydrolysis.
##EQU1##
Namely, in the case where all alkoxy groups of the tetraalkoxysilane have
been hydrolyzed, the degree of hydrolysis is 100%, and in the case where
two alkoxy groups have been hydrolyzed, the degree of hydrolysis is
represented as 50%. The degree of hydrolysis is possible up to 100%.
However, the 100% hydrolyzate is complete solid of SiO.sub.2. A product
wherein the degree of hydrolysis exceeds 70%, is a gel like gelatin, or
solid; and a product wherein the degree of hydrolysis is from 65 to 70%,
is highly viscous and is likely to react with moisture present in a small
amount in air and will be gelled, whereby the storage stability will be
poor and handling will be very difficult. Accordingly, in the present
invention, it is necessary to use a silicate oligomer having a degree of
hydrolysis of up to 65%, and it is preferred to employ an oligomer having
a degree of hydrolysis of from 0 to 50%. The tetraalkoxysilane monomer
corresponds to a degree of hydrolysis being 0 and will be referred to as
an oligomer having a degree of hydrolysis of 0 in this specification.
The amino alcohol used in the present invention is an amino alcohol having
at least one primary, secondary or tertiary nitrogen atom and one or two
hydroxyl groups, and it may be gas or liquid. Otherwise, it may be solid
so long as it is capable of being dissolved in the silicate oligomer or
capable of being reacted with the silicate oligomer to form a liquid.
Specifically, it is preferable the one having from 1 to 30 carbon atoms
such as methanolamine, ethanolamine, diethanolamine,
N-methyldiethanolamine, monomethylethanolamine, dimethylethanolamine,
hexanolamine, decyl alcohol amine, pentadecyl alcohol amine, eicosyl
alcohol amine or melissyl alcohol amine. However, from the viewpoint of
the handling efficiency and the safety, a liquid is preferred, and the one
having from 2 to 10 carbon atoms is preferred.
The reaction of the silicate oligomer with the amino alcohol may be
conducted by mixing the silicate oligomer and the amino alcohol so that
the ratio of the alkoxy equivalent of the silicate oligomer to the
hydroxyl equivalent of the amino alcohol becomes a prescribed level and
removing from this mixture the alcohol (resulting from the silicate)
corresponding to the hydroxyl equivalent. The weight of the silicate
oligomer containing one mol of an alkoxy group is one alkoxy equivalent,
and when R in the formula (I) is a methyl group, the alkoxy equivalent is
represented by the formula (III):
##EQU2##
When the degree of hydrolysis is 40%, n=0.8, hence, one alkoxy equivalent
is 48.
The weight of the amino alcohol containing 1 mol of a hydroxyl group is one
hydroxyl equivalent, which is represented by the formula (IV) using the
hydroxyl value of the amino alcohol, or the molecular weight and the
number of functional groups.
##EQU3##
In the case of ethanolamine, the molecular weight is 61, and the number of
hydroxyl groups is 1, hence one hydroxyl equivalent thereof is 61.
The equivalent ratio for the reaction of the silicate oligomer with the
amino alcohol is selected within a range of hydroxyl equivalent/alkoxy
equivalent=0.1-1.0, preferably 0.4-1.0. The desired equivalent ratio
varies depending upon the method of use of the obtained product. In a case
where the amino alcohol may remain in excess, the amino alcohol may be
used in an excess amount, and likewise in a case where the silicate
oligomer may remain, the silicate oligomer may be used in excess. However,
the larger the proportion of the amino alcohol, the higher the activity as
the dehydrating agent, and when used for the urethane resin, the higher
the activity of the reaction for urethane. Accordingly, it is necessary to
determine the reaction equivalent ratio depending upon the particular use.
If this equivalent ratio is less than 0.1, the effects as a dehydrating
agent tend to be very small.
The reaction may be conducted by introducing prescribed amounts of the
silicate oligomer and the amino alcohol into a reactor, followed by
heating to a temperature of from 70.degree. C. to 200.degree. C.,
preferably from 100.degree. C. to 160.degree. C., and removing the
resulting alcohol. The alcohol and the amino alcohol are likely to lead to
azeotropy, and an adequate care is required. This reaction may be
conducted in air or in various inert gases, and it may be conducted under
atmospheric pressure or reduced pressure. A catalyst may or may not be
used. As the catalyst, a usual catalyst for esterification or catalyst for
ester exchange may be employed. Specifically, it is possible to employ,
for example, an alkyl tin, magnesium acetate, calcium acetate or a
titanate.
The resulting product i.e. the amino group-containing silicate composition
has high reactivity with water, and an adequate carefulness is required in
its handling to avoid the contact with moisture. The viscosity (at
25.degree. C.) of the amino group-containing silicate composition thus
obtained is usually from 0.001 to 1000 poise, preferably from 0.01 to 100
poise, more preferably from 0.01 to 10 poise.
The reaction product (the amino group-containing silicate) obtained by the
present invention is considered to have constituting units of the
following formulas. (1) In a case where the amino alcohol has one hydroxyl
group
Si(OR).sub.4-2n-x O.sub.n (OR').sub.x (V)
(wherein n is a real number of from 0 to 1.3, .sub.x is a real number of
from 0.4 to 4, R is an alkyl group, and R' is a monovalent hydrocarbon
residue having an amino group.) (2) In a case where the amino alcohol has
two hydroxyl groups
Si(OR).sub.4-2n-2y O.sub.n (OR"O).sub.y (VI)
(wherein n and R have the same meanings as in the formula (V), .sub.y is a
real number of from 0.2 to 2, and R" is a bivalent hydrocarbon residue
having an amino group.)
The amino group-containing silicate composition of the present invention
reacts with water to form an amino alcohol and silicon oxide. By utilizing
this reaction, it can be used as a dehydrating agent. The dehydrating
agent of the present invention is not suitable for removal of a large
amount of water, but is suitable for removing moisture at a level of a few
hundreds ppm. By the reaction with water of this level, silicon oxide will
not form in such a large extent as it precipitates. Further, particularly
when it is used for dehydration of the raw material in the urethane field,
the resulting amino alcohol serves as a urethane-forming catalyst, and the
amino alcohol will further react with the isocyanate so that it is taken
in the resin. And, silicon oxide at a level of a few hundreds ppm will not
adversely affect the property of the resin. Especially, this amino
groupcontaining silicate composition readily reacts with water, and it
takes only a few hours to reduce a moisture of a few hundreds ppm to a
level of a few tens ppm.
The composition of the present invention can be used as a dehydrating agent
simply by adding the composition of the present invention in a necessary
amount to the liquid to be dehydrated, followed by mixing uniformly and
leaving the mixture to stand at room temperature for a few hours. To
shorten the time for dehydration, the amount of the composition of the
present invention may be increased, or the temperature of the liquid to be
dehydrated may be raised. Further, the dehydration treatment is preferably
conducted in an atmosphere such as nitrogen or dried air which does not
contain moisture as far as possible.
The amount of the dehydrating agent composed of the composition of the
present invention to be used, is determined depending upon the types of
the silicate oligomer and the amino alcohol used as the starting materials
and the amount of water in the liquid to be dehydrated.
Namely, the silicate oligomer to be used in the present invention and the
structural units of the amino group-containing silicate compositions as
the reaction products, are represented by the above formulas (I), (V) and
(VI).
And, the amino silicates of the formulas (V) and (VI) can react with (2-n)
mol of water, respectively.
Accordingly, if the type of the alkyl group (R) of the raw material
silicate compound, the degree of hydrolysis (n/2.times.100), the type of
the amino alcohol (R',R") and the reaction equivalent ratio of the
silicate compound to the amino alcohol (x/(4-2n) or 2y/(4-2n)) are known,
the amount of water which can be dehydrated by a prescribed amount of the
amino group-containing silicate composition can be calculated.
Practically, the composition of the present invention is added preferably
in an amount of from 1 to 5 times, preferably from 1 to 3 times, the
calculated amount.
The composition of the present invention may preferably be used
particularly for the dehydration of the raw material for the preparation
of a urethane resin. The urethane resin is obtained by the dehydration
condensation reaction of a polyol with an isocyanate. However, if water is
present in the starting material, particularly in the polyol, carbon
dioxide gas will be formed by the reaction of water and the isocyanate,
thus leading to foaming. As described in the foregoing, the composition of
the present invention is capable of removing moisture at a level of a few
hundreds ppm as a dehydrating agent, and yet, after the dehydration, it
serves as a catalyst for the urethane reaction. Therefore, the dehydrating
agent can be used as it is for the reaction for the production of urethane
without necessity of removing it.
Likewise, it is particularly useful for dehydration of the raw material for
the production of an epoxy resin.
In a case where the amino group-containing silicate composition of the
present invention is to be used for a urethane resin, the amino
group-containing silicate composition is used as a dehydrating agent for
the polyol component. Namely, to the polyol component, a urethaneforming
catalyst is added as the case requires, and a necessary amount of the
amino group-containing silicate composition is added thereto, and the
mixture is left to stand for a few hours. After confirming that the
moisture in the polyol mixture is lowered to a level not higher than the
objective value (the prescribed value), an isocyanate component is added
to this polyol mixture at a equivalent ratio (NCO/OH) of from 1.00 to
1.35, and the mixture is stirred and injected in a mold, followed by
curing to prepare a urethane resin.
The polyol component may be those commonly used for the preparation of
urethane, including a polyether polyol obtainable by ring-opening addition
of an alkylene oxide such as ethylene oxide or propylene oxide using as an
initiator water or a hydroxy compound having from 2 to 8 active hydrogen
atoms, such as ethylene glycol, propylene glycol, glycerol or
trimethylolpropane; a polyester polyol obtainable by reacting a dibasic
acid such as adipic acid or phthalic acid with a polyhydric alcohol such
as ethylene glycol, propylene glycol or 1,4butanediol; and a polymer
polyol obtained by graft polymerizing acrylonitrile and styrene to the
abovementioned polyether polyol.
The isocyanate component may be an aliphatic isocyanate such as ethylene
diisocyanate, 1,4tetramethylene diisocyanate, 1,6-hexamethylene
diisocyanate or 1,12-dodecane diisocyanate; an alicyclic isocyanate such
as cyclobutane-1,3-diisocyanate, or cyclohexane-1,3- and
-1,4-diisocyanate; an aromatic isocyanate such as m-phenylene
diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, or
4,4'-diphenylmethane diisocyanate; or mixtures, oligomers or
carbodiimide-modified products thereof.
The urethane-forming catalyst which may be used as the case requires,
includes an amine compound such as triethylenediamine, N-methylmorphorine,
or tetramethylhexamethylenediamine; and a tin compound such as stannous
octoate, stannous oleate, or dibutyltin dilaurate. These catalysts may be
used alone or in combination. When such a catalyst is used, it is
preferably added in an amount of from 0.01 to 10 parts by weight per 100
parts by weight of the polyol component.
In addition, a crosslinking agent such as ethylene glycol, 1,4-butanediol,
or triethanolamine, a pigment such as carbon paste, or a silicone-type
foam stabilizer, may be added as the case requires.
Further, the amino group-containing silicate composition of the present
invention may be used also as a curing agent at the time of preparing an
epoxy resin. Namely, to an epoxy compound having at least one group of the
formula
##STR2##
per molecule, the amino group-containing silicate composition of the
present invention is reacted in the presence or absence of a catalyst, so
that the epoxy equivalent/amine equivalent would be a substantially equal
ratio. Specifically, to an epoxy compound as disclosed in e.g. U.S. Pat.
Nos. 2,633,458, 2,658,885, 3,373,221 or 3,377,406, the amino
groupcontaining silicate composition of the present invention may be added
and reacted for curing. Especially, an amino group-containing silicate
composition using a silicate oligomer having a low degree of hydrolysis
has a low viscosity as compared with conventional epoxy curing agents and
a high boiling point as it contains silicon, hence its handling is very
easy. The catalyst which may be used for the above reaction includes
cationic and anionic catalysts including a tertiary amine (including
guanidine, biguanide and imidazole), a boron complex salt, a Lewis acid,
an inorganic acid, a short chain amide, dihydrazide and a titanic acid
ester. The amount of the catalyst is preferably about a few parts by
weight per 100 parts by weight of the epoxy compound. In addition, a
diluting agent, a flexibility-imparting agent or a filler, may be added as
the case requires.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a graph showing the changes in the water contents in polyols
containing various dehydrating agents prepared in Example 2 of the present
invention. In the Figure, (a) to (d) represent the following,
respectively:
(a) Polyol/amino group-containing silicate composition of the present
invention=100/1.8
(b) Polyol/tetraethylsilicate=100/1.0
(c) Polyol/50% hydrolyzate of tetramethylsilicate=100/0.6
(d) Polyol/tetraethylsilicate/dimethylethanolamine=100/1.0/1.7
EXAMPLES
Now, the present invention will be described in detail with reference to
Examples. However, it should be understood that the present invention is
by no means restricted to such Examples.
EXAMPLE 1
1 mol of tetraethylsilicate and 4 mols of dimethylethanolamine were
introduced into a reactor and heated to 140.degree. C. under a nitrogen
atmosphere. The resulting ethanol (about 4 mols) was removed to obtain an
amino group-containing silicate composition. The product has a very high
reactivity with water, and it is necessary to take a due care in its
handling. The viscosity was measured in a nitrogen atmosphere and found to
be 0.8 cps (25.degree. C.).
EXAMPLE 2
Dehydration of a polyol was conducted by means of a dehydrating agent (a)
composed of the composition of the present invention and other dehydrating
agents (b) to (d).
To a polyol mixture (hereinafter referred to simply as "polyol") comprising
GP-1000 (a polyol prepared by adding propylene oxide to glycerol, hydroxyl
value: 168, manufactured by Sanyo Kasei K. K.) and DPG (dipropylene
glycol) at a ratio of 70/30 (weight/weight),
(a) the amino group-containing silicate composition obtained in Example 1
was added at a ratio of 100:1.8 (the polyol:the amino group-containing
silicate composition, weight/weight),
(b) tetraethylsilicate was added at a ratio of 100:1.0 (the polyol:the
tetraethylsilicate, weight/weight),
(c) a silicate oligomer (hereinafter simply referred to as "oligomer")
obtained by hydrolyzing 50% of tetramethylsilicate, was added at a ratio
of 100:0.6 (the polyol:the oligomer, weight/weight), and
(d) tetraethylsilicate and dimethylethanolamine were added at a ratio of
100:1.0:1.7 (the polyol:the tetraethylsilicate:the dimethylethanolamine,
weight/weight/weight), to obtain the respective mixtures, and the changes
in the water content with time were measured. The results are shown in
FIG. 1.
The conditions were such that the addition and mixing were conducted at
room temperature, and the mixtures were left to stand at room temperature,
and the water content was measured by a Karl Fischer's method.
The amount of each silicate compound added was an amount capable of
dehydrating about 3000 ppm of water.
As is evident from FIG. 1, dehydration was very slow with (b) to (d),
whereas dehydration can be conducted in a few hours with (a).
EXAMPLE 3
The mixture (a) in Example 2 (GP-1000/DPG/the amino group-containing
silicate composition=70/30/1.8, weight/weight/weight) and polymeric MDI
(NCO%: 30.6%, manufactured by MD Kasei K. K.) were reacted at a NCO/OH
equivalent ratio of 1.15 in the absence of a catalyst to obtain a
non-foamed solid urethane resin.
EXAMPLE 4
To one equivalent of a 50% hydrolyzate of tetramethylsilicate, 0.6
equivalent of monoethanolamine was introduced into a reactor and reacted
in the same manner as in Example 1, whereupon the resulting methanol was
removed. The obtained amino group-containing silicate composition has a
very high reactivity with water in the same manner as in Example 1, and it
is necessary to take a due care in its handling. The viscosity in a
nitrogen atmosphere at 25.degree. C. was 310 cps. 1.2 Parts by weight of
this amino group-containing silicate composition was added to 100 parts by
weight of the same "polyol" as used in Example 2, and the water content in
the polyol was measured as the time passes. The results are as follows.
______________________________________
Time passed (hr)
0 2 4 6 10
______________________________________
Water content (ppm)
680 180 80 50 30
______________________________________
EXAMPLE 5
The amino group-containing silicate composition obtained in Example 4 and
Epicote 828 (manufactured by Shell Chemical Co.) were reacted at an epoxy
equivalent/amine equivalent=1/1. The obtained resin was equivalent to an
epoxy resin cured by a commercially available epoxy resin curing agent
(Versamid 125, manufactured by Henkel Hakusuisha K. K.).
INDUSTRIAL APPLICABILITY
The amino group-containing silicate composition of the present invention
has a high reactivity with water, is capable of reducing the water content
to a very low level and is a low viscosity liquid, whereby its handling is
easy and it is useful as a dehydrating agent for various chemical
substances.
Further, as it is different from conventional solid dehydrating agents, a
process step such as filtration is not required depending upon the field
of its application. Further, since it contains a nitrogen atom, it is
useful also as a catalyst or a curing agent for a urethane resin or an
epoxy resin.
The foregoing characteristics are very effective particularly for the
production of a non-foamed urethane resin.
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